1. Technical Field
This invention relates to a connector formed on a main-card board for connecting to the main-card board in a replaceable manner a sub-card board having various functions, particularly a sub-card board connector wherein a grounding method between a connector and a sub-card board has been improved, a sub-card board, a modem sub-card, and a computer having this connector.
2. Description of the Related Art
In recent years, along with the dramatic diffusion of the Internet and that of portable telephones in addition, mounting a modem function and so on a PC has become inevitable. In particular, this modem function is one of the most important functions for a super-slim notebook PC of superior portability. Incidentally, to connect a sub-card board having such various functions to a main-card board, it is necessary, especially for a sub-card board emitting an electromagnetic wave such as a modem function, to securely ground the sub-card board in order to control electrical noise. Also, a modem needs to be certified in each individual country to which it is shipped, and to facilitate such certification, it is necessary to make the sub-card board replaceable. Moreover, it is required that the sub-card board is easily removable for upgrading and maintenance of the modem's functions.
FIG. 6 is a diagram showing an example of connecting a conventional sub-card board to a main-card board via a connector. In FIG. 6, 51 is a cover, 52 is a main-card board, 53 is a sub-card board such as a modem, and 54-1 and 54-2 are connectors, namely 54-1 is a connector fixed on the main-card board 52 side, 54-2 is a connector fixed on the sub-card board 53 side, 55 is a screw, and 56 is a stud. As FIG. 6 shows, conventionally, in the event of connecting sub-card board 53 to main-card board 52 via connectors 54-1 and 54-2, sub-card board 53 was connected to main-card board 52 by using straight-type or right-angle-type connectors 54-1 and 54-2 to be fixed with screws 55 at a few locations. And the grounding of sub-card board 53 to main-card board 52 and cover 51 was performed by using screws. Thus, while it had a sufficient grounding function, a space for screwing became necessary or it took time for placement and removal of sub-card board 53, which was a factor of increasing repair and assembly costs.
As a connector for solving the above-mentioned problem, a connector mainly used for a memory card is known. This connector is a connector formed on a main-card board for connecting to the main-card board in a replaceable manner a sub-card board having various functions, the connector comprising a connector body having an electrode pattern in contact with a terminal formed on an end face of the sub-card board; and latch supporting parts having latches from the connector body along the main-card board for setting the sub-card board on the connector body obliquely to the main-card board and, from that state, fixing the sub-card board by suppressing the reaction force in pressing the sub-card board against the connector board so that it should be along the board.
The basic structure of this connector is the same as the embodiment of the present invention explained later as FIG. 1 and FIG. 2. As for the connector of the above-mentioned structure, placement and removal of a sub-card board are simple, and the occupied space can also be made smaller since it is not fixed by screws. However, there was a problem that, while it was conventionally well grounded by using screws, a ground with screws cannot be used since there is no screw. Here, there was a problem that, if grounded with a connector terminal, the wiring used on the terminal is too thin to be sufficient and also the number of the usable terminals is limited accordingly. In addition, there was a demand for grounding around a sub-card board to eliminate radio disturbance such as EMI. Thus, it has been desired that a structure allowing good grounding be also found in this type of connectors.